The present invention relates to devices that insert and remove a collet, and in particular, it relates to a tool and method to insert and remove a collet into and from a collet chuck of a lathe.
Collets have exterior chuck engaging surfaces that engage interior compression surfaces of the chuck. In lathe-type machines, a work piece is inserted into a collet which engages the work piece and holds it tightly. The typical collet is provided with a plurality of fingers separated by slots. The work piece is inserted in a work engaging opening defined by the fingers. The fingers are joined such that the fingers tend to be biased outward away from the work engaging opening and towards the interior compression surfaces of the chuck.
Whenever a different sized work piece must be machined, the collet must be changed to accommodate the new structural dimension. This is a relatively common occurrence in some situations because the collets may only have a 0.25" throw. In some machines, it is very difficult to remove the collet from the machine because the chuck must be partially disassembled to release the collet. In addition, it sometimes is difficult to handle a collet because of its smooth surface and lack of areas to easily hold the collet while inserting or removing the collet from the chuck.
Patents that describe collet insertion and removal tools and methods for doing the same include Williams U.S. Pat. No. 4,768,269 and Williams U.S. Pat. No. 4,821,401. The Williams '269 and Williams '401 patents describe a tool with outwardly extending fingers for engaging apertures and gripping the collet. The apertures are formed in the face of each segment of the collet. The collet is gripped by the tool when it is in a compressed condition, so that as it is released by the chuck, the springs of the collet force the collet segments outwardly forcing the side walls of the apertures against the fingers and frictionally locking the collet to the tool.